Sorting match cases by H2O capacity

[savagedasher]

I watched Benchrest shooter do it without knowing
They tossed the case in the trash
But why not do both

 

[BartsBullets]

I watched Benchrest shooter do it without knowing
They tossed the case in the trash
But why not do both

Doing both is fine, but between fighting the scale to make sure it’s properly zeroed. Then half way through wondering if I’m keeping the dome of water the same for 100 cases. It’s just easier for me to test the velocity.

In reality the only thing that matters is what velocity does the case produce. So the labradar gives me that.

Bart

 

[BartsBullets]

Bart -

Curious, do you shoot any, but specifically the cases that are different a second time for verification?

Mike,

Normally only cases that gave me an odd reading that were high or low I’d double check. They didn’t change after retesting.

I cleaned the gun after every 12 shots to try and keep the barrel and test consistent. This was with a 6BR. Below is a pic of the brass color coded.

 

[savagedasher]

I don’t have the bubble problem
Or case lingth
I made a tool that forces the air out along with check the volume off the shoulder so it is the same

 

[BartsBullets]

I don’t have the bubble problem
Or case lingth
I made a tool that forces the air out along with check the volume off the shoulder so it is the same

You’re way ahead of me!!!

 

[savagedasher]

You’re way ahead of me!!!

I will ship you a prototype Crude but works

 

[BartsBullets]

I will ship you a prototype Crude but works

You’re the Man!

Bart

 

[dsculley]

If I were going to sort brass I would use Bart's method. That way, I am learning about my brass as well as practicing my shooting/wind reading. I have limited time. I find practice more beneficial than sorting brass, bullets & primers. I started F-Class this year and while i am not shooting clean targets I am not doing bad considering the winds where I am shooting. I know that with practice in no wind conditions I can shoot under .5 moa, with my best day in the .3's without any sorting (now this is at 300 yds, not 600 or 1,000 but that is the longest I have for practice).

If you really want to test your sorting methods, get 20 sorted cases and 20 random cases, load them identically then shoot a blind bag test. Have someone put them in two boxes/bags marked 1 & 2 so that only they know which is which. Then go to the range and shoot all 40 rounds, one target for each set. Shoot them round robin (1 from set 1 then 1 from set 2, etc. If possible, shoot them at the range you plan to shoot. Then compare the groups to see how much difference the sorting made.

As we have seen in load development, there is not a straight-line relationship between MV and POI change. I believe that if your charge is truly on a node then the .6 - 1.05% variance in volume will not cause a significant change in POI and that for most shooters that POI change will get lost in their wind call. Even if all the sorting brings a .5MOA gun down to a .2MOA gun the difference is .3MOA. If you make your wind calls perfect that is enough to take you out of the x ring but not the 10 ring. At 1,000 yds that 1.5 inches on each side does give you a bit of wiggle room but not much for missing your wind call. Or put another way, if you can call your wind within 1.5 inches then all the work helps. If you can't, then it really doesn't.

 

[Ned Ludd]

Here’s another thought...Instead of sorting by H20, I use my labradar to sort my brass. For the Nationals I took 100 cases, loaded them as identically as possible and checked the velocity with the labradar.

With a clean barrel I’d fire two shots to foul the barrel and get it up to speed. Then I’d start recording the velocities from the match brass. To keep up with the results I’d just write the velocity on the side of the case. Then sorted accordingly!

If you can zoom in on the cases on the table you can see the velocities on the side.
Bart


View attachment 1078832

I like this idea.

You stated in a later post that cases seem to hold close to the same velocity on subsequent reloadings (good or bad), after an initial velocity sort. Many of us think about neck tension, charge weight, primers, and other things, in addition to case volume, as potential sources of velocity variance. Your results seem to suggest that the case itself may be the biggest part of velocity variance, or else you have effectively eliminated those other sources of velocity variance in your reloading process. If the other potential sources of velocity variance besides the cases themselves were causing any of your velocity outliers, you would expect to see just as many outliers on subsequent reloadings, regardless of the initial velocity sorting.

With somewhat of a similar idea in mind, I have often measured cases in a variety of ways (dimensions, volume, etc.) after recording velocity to try and determine exactly what was different about the velocity outlier cases. To date, I have not been successful in identifying any specific property that was consistently different for cases that gave either inconsistently high or low velocities, relative to the average.

So, do you have any thoughts on exactly what might be different/unique about the cases themselves that allow them to be sorted into consistent velocity groups? Do you think it's all about case volume? Or does some other factor such as neck tension seem remain relatively constant once the cases have been velocity-sorted?

 

[BartsBullets]

Ned,

I think case volume is the primary culprit. Also to check cases this way you need a pretty good scale. For example I have 3 chargemasters. The best I can hope for using those to dispense powder is an ES around 10 to 15. With my Fx 120i ES will get well into the single digits.

There’s alway going to be some variation between primers, and powders, time between shots. I haven’t seen where neck tension plays much into changing velocity. Definitely tune, but not velocity.

A long time ago back when it was easy to blow a primer (Old Hall and Panda actions). I noticed when I’d blow a primer say out of 10 shots loaded the same. The case that blew was always the heaviest.

Some thoughts about low extreme spreads...

Low Extreme Spreads does not mean you have a TUNED rifle. This is very confusing to many shooters. You can shoot horrible groups and have very Small ES.

ES is an indicator of how well your reloading technique is. Not how well your rifle is tuned.

Also IF you cannot get low extreme spreads. It may not be your reloading. It can be the ignition system on your rifle.


Bart

 

[savagedasher]

The first thing you do in making a race motor is to make the cylinder head have the same volume on each. Cylinder
You cc them
Being a old racer I felt the the cases
Needs. To be done
But when trying I found the the bubble and the wet case we giving faults errors
So I made a tool that reduced the errors
I feel a case should be fired two times in the same chamber
U can leave the primers in or remove them a put the spent primers in bottom side up
The next problem was the amount of bubble oh the neck and the varence in neck leingth
So i solved that problem by using the shoulder for the reference area
Trust me it works

 

[BartsBullets]

The first thing you do in making a race motor is to make the cylinder head have the same volume on each. Cylinder
You cc them
Being a old racer I felt the the cases
Needs. To be done
But when trying I found the the bubble and the wet case we giving faults errors
So I made a tool that reduced the errors
I feel a case should be fired two times in the same chamber
U can leave the primers in or remove them a put the spent primers in bottom side up
The next problem was the amount of bubble oh the neck and the varence in neck leingth
So i solved that problem by using the shoulder for the reference area
Trust me it works

Sounds like great idea! This was a 6BR I only put one fireing on the cases before checking. Dasher, Bra, Grinch definitely need two.

However, I wonder if You could sort the cases while fireforming? It would be interesting to record brass velocities while fire-forming. Then recheck the finished cases again once fully formed. It might be worth a winter time project.

Bart

 

[savagedasher]

Sounds like great idea! This was a 6BR I only put one fireing on the cases before checking. Dasher, Bra, Grinch definitely need two.

However, I wonder if You could sort the cases while fireforming? It would be interesting to record brass velocities while fire-forming. Then recheck the finished cases again once fully formed. It might be worth a winter time project.

Bart

Sure anything thing yo can do helps at distance
I have got my ES around 5 by the ting I have
When you shoot a savage you need all the help you can get lol